Not every story follows just a single main character. Superhero and comic book movies are great examples of this, as an argument can be made for any one of the heroes in films like Avengers: Infinity War or Justice League to be the protagonist. The possibility of multiple protagonists grows even greater once a portal to the multi-verse is opened and out pops infinite versions of the main character. As is the case within the amazing animated sequel film, Spider-Man: Across the Spider-Verse.
With Across the Spider-Verse opening the multi-verse up even more than the first film and introducing fans to a whole new cast of Spider-People, it's clear that this story is no longer only about Miles Morales. Actually, the second film gives viewers a deeper insight into Gwen Stacy's Spider-Woman, aka Spider-Gwen, and her crucial role in the Spider-Verse franchise.
Spider-Verse's Spider-Gwen is a Pivotal Character
From the first Spider-Verse film, Spider-Gwen has played an important part in Miles' journey in becoming Spider-Man. She was the one who kept an eye on him at Visions Academy after she was transported into his dimension, Earth-1610. After that, her and Miles built the strongest relationship of all the other Spider-People he met (a strong contender being Peter B. Parker), helping inspire Miles to be his own Spider-Man instead of trying to live to the standards of his dimension's original Spidey.
In the sequel film, she is essentially Miles' connection to the Spider-Verse as she unknowingly lets him into the inter-dimensional portal she opens, eventually leading him to the Spider Society which is run by Spider-Man 2099. Plot points aside, she also is the reason Miles keeps pushing forward, both as Spider-Man and as Miles.
Both Miles and Gwen see each other as their only friend, with the role of being Spider-Man/Woman taking its toll on their personal lives. Without each other, there's a good chance they'd care a little less about the other Spider-People of the Spider-Verse, thus, making both of them the primary reason why they are so infatuated with exploring it. In other words, a big part in them wanting to travel through the Spider-Verse is so that they could see each other.
And while Miles has openly expressed his romantic interests in Gwen, she hasn't quite reciprocated the feelings, although it's unclear whether she's simply fighting those feelings. In love or not, by the end of Across the Spider-Verse, Gwen cares enough about Miles to recruit her team of Spider-People to attempt to save Miles from the clutches of his alternate self as the Prowler.
Spider-Gwen Has a Full Arc in Across the Spider-Verse
Spider-Gwen is literally the bookends of the sequel film; being the first person seen in the movie's opening sequence and the last one before it cuts to black at the end. But from that first shot of her playing drums to the last one of her leading her team of Spider-People, she was a different person.
Throughout most of the film, Gwen is just trying to escape from her own world, literally and figuratively. She keeps trying to distract herself from the tragedy of her reality in which she unknowingly killed her best friend Peter Parker, in turn making her public enemy number one in the eyes of the NYPD, whose Captain just so happens to be her father, George Stacy. She tries joining a band, but that doesn't help. Meanwhile, she has a very dry relationship with her father as he endlessly tries to pursue the arrest of Spider-Woman, aka Gwen. She also realizes that she may never see Miles again, and starts down a path just being by herself, a "lone spider" if you will.
After defeating the Renaissance Vulture with Spider-Man 2099 and Jessica Drew, she is forced to reveal her identity to her father and left with the decision to join the other Spideys as they go into the Spider-Verse, or stay in her world and face the consequences unbiasedly appointed by her police officer father. This breaks her heart, and she decides to leave her world behind.
As the film continues, she ruptures her closest relationships in one way or another; she hinders the trust between her and Miles after he finds out that she knew about the canon event in which his father would soon die, then she is kicked out of the Spider Society after helping Miles escape to his own universe (or so he thinks) and returns to her original universe.
It's here that she's forced to confront her father. She tells him that he is the reason she became Spider-Woman after being bitten by the spider, in which she wanted to use her power for the greater good. But once George turned on Spider-Woman -- even after knowing she was Gwen, his daughter -- she lost all sense of self and gave up on her core beliefs of being a Spider-Person. George then informs her he quit being a police officer in order to repair their relationship, and Gwen finally sees what it is she must do.
Gwen realizes it's not the powers or the mask that are the most important, but the relationships she's built along the way. After George gives her the inter-dimensional bracelet left behind by Spider-Punk, she decides to recruit a team of Spideys and go out to rescue Miles. She sees that in order to be a Spider-Person, she must first be Gwen, and what Gwen most desires is to conserve her close relationships. So, instead of seeing her powers as a way of proving herself to her father, she realizes her powers are just a thing to help her save the people she loves most.
Spider-Gwen Can Keep Driving the Story in Beyond the Spider-Verse
Across the Spider-Verse ends on a cliffhanger in which Miles is captured by Prowler Miles and Gwen assembles her rescue team compiled of Hobie (Spider-Punk), Margo Kess, Pavitr, as well as the return of the Spider-People from the first film, Peter B. and his daughter Mayday, Peni Parker, Spider-Ham, and Spider-Man Noir. Plot wise, she is already set up to drive the story in the third film, as it will inevitably follow her team's journey in saving Miles.
Beyond the plot, though, she has a lot to teach Miles now about companionship and why working together is better than working alone. At the end of the film, Miles has the attitude that no one is on his side and that he must go on by himself, leaving him to believe that is the burden of being Spider-Man. However, as Gwen had learned, being a Spider-Person isn't about using their powers to help better themselves, but to help the most important people in their lives and the people who need saving.
Spider-Gwen will no doubt be a central character in Beyond the Spider-Verse and will serve as a main component in driving the story further.